1. Field of the Invention
This invention relates generally to the field of resistance type exercise machines, and particularly to a machine for exercising the muscle groups of the upper torso and arms.
2. Background
A wide variety of exercise machines have been designed to develop particular muscle groups of the body. Most such machines have one or more operable members to be gripped by a user while performing exercises. The operable member is typically supported by the exercise machine so that it is constrained to follow a predetermined exercise path. The user is therefore constrained to move his or her body in accordance with the mechanical structure of the machine.
Machines of this sort provide a degree of exercise control that is in marked contrast to the use of free weights that are still favored by many athletes. Exercise movements with free weights are not restricted to follow predefined paths. On the other hand, exercise machines typically employ a pivoting exercise member with a grip that moves in an arcuate path centered at the pivot axis of the exercise member. Although this controlled movement of the exercise member is generally desirable in order to isolate the exercise to particular muscles or muscle groups, the mechanical design of prior art exercise machines does not necessarily provide an optimum path of movement.
One of the most common exercises performed with an exercise machine is a chest press exercise. The athlete is typically seated, often in a slightly reclining position. A press arm pivots on a horizontal axis and is gripped at approximately shoulder level. The press arm is coupled to a resistance mechanism, most commonly a stack of weights in which the number of weights, and thereby the resistance, can be manually selected. A pair of horizontal handgrips are provided, and quite often a pair of vertical handgrips are provided as well. The exercise is performed by pressing forward on the handgrips against the selected resistance until the athlete's arms are outstretched. When performed in this manner, the exercise emphasizes the pectorals and triceps. Changing the position of the handgrips will slightly alter the muscular emphasis of the exercise.
Variations on the traditional chest press exercise machine have been developed in order to shift the muscular emphasis of the exercise and/or improve the physiological interface. For example, U.S. Pat. No. 5,044,631 issued to Jones discloses a decline press exercise machine in which a pair of independently pivoting press arms are suspended on axes that converge in a horizontal plane. The press arms therefore move in arcuate paths that lie in vertical planes which converge inwardly with respect to the longitudinal centerline of the machine. Such an arrangement is claimed to more naturally accommodate musculoskeletal movements of the arms and shoulders.
U.S. Pat. No. 4,949,951 issued to Deola discloses an exercise device having a suspended U-shaped member resembling a conventional press arm, but with two bar members connected to the lower ends of the U-shaped member by universal joints. The freedom of movement afforded by the universal joints allows the device to be used for performing either a conventional chest press exercise or a dumbbell fly exercise.
A vertical pectoral contractor and rear deltoid machine manufactured by Body Masters Sports Industry, Inc. as model CH 504 provides a pair of exercise arms that pivot about vertical axes located approximately in line with the user's shoulder joints. To exercise the pectoral muscles, the user grasps handgrips suspended from the overhead exercise arms and rotates them forwardly and inwardly through symmetric circular arcs that are concave with respect to the user's torso.
A pectoral isolator manufactured by Galaxy Sport as model 142 also provides a pair of pivotal exercise arms. However, in this machine, the pivot axes are well forward and outboard of the seating position. The user begins the exercise with the handgrips out to each side and rotates the exercise arms forwardly and inwardly in circular arcs that are convex to the user's torso.